Method of tire building and material used therein



Jan. 17, 1950 H. DREYFUS 2,494,649

METHOD OF TIRE BUILDING AND MATERIAL USED THEREIN Filed Oct. 3, 1945WEI-T OFA FIBRE FORMING HOMO POLVMEF\ OF ETHYLENE WARP OF REGENERATEDCELLULOSE.

ATTORNEYS Patented Jan. 17, 1950 METHODOF TIRE BUILDING AND MATERIALUSED THEREIN Henry Dreyfus, deceased, late of London, England, by ClaudeBonard, administrator, London, England, assignor to Celanese Corporationof America, a corporation of Delaware Application October 3, 1945,Serial No. 620,184

" In Great Britain July 24, 1944 Section 1, Public Law 690, August 8,1946 Patent expires July 24, 19.64

To facilitate handling of the layers of cord, it is common for the cordsof each layer to be interwoven with relatively weak and widely spacedweft yarns to form a so-called tyre fabric. In the finished tyre theseweft yarns are redundant.

Their presence hampers the building up of the tyre in the optimum formand they may produce wear in the cords.

Various methods of avoiding the dimculty referred to above have beenproposed. Thus, for example, it has been proposed to form the weft ofunvulcanized rubber threads. The elastic properties of these threads,however, introduce serious difflculties in weaving the tyre fabric andavoiding subsequent distortion thereof. An alternative suggestion is toform the weft of plastic material having a basis of vulcanised naturalrubber. The great extensibility and relative weakness of such threads,however, also introduces dimculties in weaving the tyre fabric and inits subsequent manipulation. It has therefore been proposed to form theweft of threads having a basis of unvulcanised natural rubber and toemploy a non-elastic substance, for example gelatine, either as a sizeapplied to the weft threads before weaving or as a constituent of thecomposition from which the threads are formed, with a view totemporarily suppressing the elasticity of the rubber. The substanceemployed to suppress the elasticity is removed after the tyre fabric hasbeen woven. and before the building up of the tyre-body. When suchmethods are adopted, however, the fact that the rub J 2 Claims. (Cl.154-14) her-like elasticity of the weft threads is restored before thebuilding up of the tyre-body introduces difllculties in-manipulation.

A method representing an improvement on the methods referred to above isdescribed in United States Patent No. 2,147,736 according to which theweft is formed of an organic derivative of cellulose which, at thetemperature of vulcanisation, melts, disintegrates, or loses itsstrength.

In the tyre fabrics or like textile re-inforcing structures of thepresent invention, the weft is composed of fibre-forming material whichdoes not exhibit rubber-like elasticity at ordinary temperature andwhich is adapted when heated, e. g. during vulcanisation of the tyre, tomerge withv the rubber'or rubber-substitute forming the basis of thetyre-body.

The drawing shows a diagrammatic view of a type of woven tyre fabric.

The weft threads of the fabrics of the invention may melt at thetemperature of vulcanisation and form solid solutions with the rubber ofthe tyre-body, or they may, at that temperature, develop sufiicient tackto merge with the rubber without melting. The weft threads shouldpossess suflicient strength to undergo the weaving operation and to keepthe cords forming the warp of the fabric in position during thesubsequent manipulation involved in incorporating thefabric in thetyre-body.

The use in the tyre fabrics of the invention of a weft which merges withthe rubber on vulcanisation makes possible the use of high tenacitycords of smaller cross-sectional area than could be used if allowancehad to be made for the weakening efiect on such cords of constantrubbing contact with weft yarns during the use of thetyre. Thus theinvention is important in enabling the advantages of high tenacity cordstobe realised to the full. Moreover the disappearance of the weft duringvulcanisation. facilitates adhesion of the rubber to the cords.

Suitable materials from which to form the weft threads are linearpolymers which are hydrocarbons and do not exhibit rubber-like elas-Numbers 2,346,759 and 2,324,583. The cords may ticity at ordinarytemperatures. The preferred contain a lubricant as described in UnitedStates material from which to form the weft threads is Patent No.2,201,992. Tricresyl phosphate may polythene. Another hydrocarbonpolymer that be employed with considerable advantage for this can beused is polystyrene. purpose.

Rubber derivatives can also be used as a basis Before rporation in thetyrey the cords for the weft threads. Examples of rubber demay be givena treatment adapted to facilitate rivatives are chlorinated rubber,rubber hydroadhesion ee e ty e cords and the rubber chloride,hydrogenated rubber, oxidised rubber, f the yr y. This treatment may,for exand cyclic rubbers obtained for example by re- 1 ample. comprise hpplication to the cords of acting upon rubber with polyvalent metallichalrubber ieteX or other p r ion of ru ber or a ides or tulphur-containing oxy-acids or th rubber-like substance, or of asolution of rubber chlorides of such acids. Among the most suitorlilhher-like substance. or of pe ons o able rubber derivatives for thepurpose are the solutions containing in addition to the rubber orderivatives obtainable by reacting upon rubber rubber-like substance,synthetio resin. for ex- (or other polymerised dienes, e. g.poly-butadiene a p a thermosetting condensation p od c of andco-polymers of butadiene with styrene with m l ehyde or a like actingaldehyde with a para-phenol sulphonic acid, para-toluene sulp W h a r amen is given to the phonyl chloride and like sulphonic acids and 5111-cords it Wm usually be most convenient o pp y phonyl chlorides, or withsulphuric acid. the tree-ting agent to the y fabric as a whole.

Materials from which weft threads having the Naturally. When this isdone. are must be taken desired properties can be formed ar also t bthat the nature of the treatment is not such as found among celuloseethers containing radicles to roy or duly weaken the weft of the yre ofhigher aliphatic mono-hydric alcohols, i. e. i to Prevent it frommerging W th the alcohols containing 5 or more carbon atoms for rubberduring Vuioenisfltionexample, amyl cellulose, amyl ethyl cellulose, Thefollowing x mp l rates the invenhexyl cellulose and hexyl ethylcelluose. tion:

A further aternative is to employ for the weft, Example threads ofnatural rubber which have been lightly A tyreword is made by doublingtogether 3 I vulcanised, for example by means of sulphur of 733 deme r nchloride in the cold while highly stretched, the above s g g g ii gi gmgm degree of vulcanisation being suflicient to premade by completesaponificatioil of ahigh vent the contraction of the threads at ordinaryyam made by stretching dry spun can 1 temperatures, so rendering themsubstantially free from rubber-like elasticity at such temperafgi izgggf m steam to about 10 tunes its om tures, but insufiicient to preventthem merging A t bri with the rubber stock at the temperature of g @1 13g:

vulcanisation of the tyre body. tamed b y cold-drawing a thread ofheavier denier vamils texme mammals i be empbyed as to about 500% of itsoriginal length, as the weft. the of warp cords m the P fabrics Thefabric is impregnated at ordinary temof the mventlzn' Among such i 1915i perature with a solution of rubber in toluene, said regenem cepulosep0 y exame y solution having a viscosity of about 10 centistokesadipamide like linear-condensation polymers at 250 C" and is dried at atemperature of to and mllmnyhdene 11mm The textile mate 0. in a currentof hot air. It is then coated rial employiad bestmng'water'resistant'ca' 45 on the calender with a vulcanisablenaturalpable of being umted to the rubber of the tyrerubber mix and t tsuitably shaped lengths body and w to wltiistapd the temperatures forbuilding up the tyre-carcase. A pneumatic untered and in the runningtyre is then built up, its carcase being formed of of the tyre withoutundesirable loss of tenacity. layers of the impregnated fabric. The tyreis It is preferred to employ the material for vulcanised under the usualconditions and durthe warp, cords composed of high tenacity fibres mgthis operation the weft threads lose their (preferably continuousfilaments) of regenerated identity and merge with the rubber cellulosesuch as are obtained by stretching cellu- The invention has beendescribed with pap lose aFetate yams or hot water or an ticularreference to the construction of tyre faborgiamc .stretchasslstmg agent:to many times 55 rics for pneumatic tyres having a. basis of rubber.9ngma1 length and iammfymg the result The fabrics of the invention canalso be employed mg hlgh tenac1ty cenu1ose acetate yams however in theconstruction of pneumatic tyres tween the stretclnng and saponiflcationstages of rubber substitutes, e. polybutadiene, pol? yams may 1f desuedbe Shrunk by the chloroprene, co-polymers of butadiene or isoaction ofmethylene dichloride or other shrinking .0 prene with monmolefimccompounds such as agent, to increase the extension. By such methst mmand isobut lane and other as and ads regenerated cellulose yarns oftenaclties rangclpolymers of dieflea 52 1,? the mg from 2 or 3 grams perdenier or less up 6 vention can also be applied in the construction ofor more grams per denier can be obtained. It is reinfomm fabrics forother articles hm mi of special advantage in the production of such asbasis of Ember or a rubbepsubsfitute and tyre cords to employ celluloseacetate or high quiring a weft-less cord reinforcement, e. g. in

viscosity i. e. a'cellulose acetate of which a 6% driving belts orconvey belts of rubber baht solution in acetone at 25 C. has a viscosityat orambber substitute least 40% and preferably from 40 to r even Havingdescribed the invention, what it is de- 200% of that of glycerine at thesame tempera- 10 siredtosecure by tt p t t ture- The e of such highviscosity cellulose 1. A tire fabric for pneumatic tires, said fabricacetates enable cords to be produced which are of having a-weft composedof a g 4 m homoh enacity even when wet. polymer of ethylene and a warpof continuous Suitable constructions for the warp cords will filamentyams of regenerated cellulose having a be found for example in UnitedStates Patents 7| tenacity of ,1; tz grams per denier,

2 grams per denier.

2. Process for the manufacture of pneumatic tires, wherein the tirecarcass is built up of layers comprising a tire fabric coated with avulcanizabie natural rubber mix, said tire fabric having a weft of afibre-forming homopolymer of ethylene and a warp of continuous filamentyarns of regenerated cellulose having a tenacity of at least 7 CLAUDEBONARD. Administrator of the Estate 0/ the Said Henry Dreyfus.

REFERENCES CITED The following references are of record in the file ofthis patent:

Number Number

1. A TIRE FABRIC FOR PNEUMATIC TIRES, SAID FABRIC HAVING A WEFT COMPOSEDOF A FIBRE-FORMING HOMOPOLYMER OF ETHYLENE AND A WARP OF CONTINUOUSFILAMENT YARNS OF REGENERATED CELLULOSE HAVING A TENACITY OF AT LEAST 2GRAMS PER DENIER.
 2. PROCESS FOR THE MANUFACTURE OF PNEUMATIC TIRES,WHEREIN THE TIRE CARCASS IS BUILT UP OF LAYERS COMPRISING A TIRE FABRICCOATED WITH A VULCANIZABLE NATURAL RUBBER MIX, SAID TIRE FABRIC HAVING AWEFT OF A FIBRE-FORMING HOMOPOLYMER OF ETHYLENE AND A WARP OF CONTINUOUSFILAMENT YARNS OF REGENERATED CELLULOSE HAVING A TENACITY OF AT LEAST 2GRAMS PER DENIER.